1. Field of the Invention
The technical features of this document relate to wireless communications, and more particularly, to a method and apparatus for processing data associated with handover in a wireless network.
2. Related Art
The Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) which is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) is introduced as 3GPP Release 8. The 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) for a downlink, and uses single carrier frequency division multiple access (SC-FDMA) for an uplink, and adopts multiple input multiple output (MIMO) with up to four antennas. In recent years, there is an ongoing discussion on 3GPP LTE-Advanced (LTE-A), which is a major enhancement to the 3GPP LTE.
The 3GPP LTE system may provide closed subscriber group (CSG) services, which can be provided only to a certain group of subscribers, to improve quality of service. A base station (BS) capable of providing CSG services can be referred to as a Home eNodeB (HeNB), and a cell serving CSG members can be referred to as a CSG cell.
In a network system which includes the HeNB, a PDN connection based local IP access (LIPA) can be supported. The LIPA enables an IP-capable UE connected via the HeNB to access other IP-capable entities in the same residential/enterprise IP network without a user plane traversing the mobile operator's network except HeNB subsystem.
Under the current 3GPP specification, the LIPA PDN connection is restricted to the CSG cell. Therefore, if the LIPA PDN connection is carried over across cells, it can cause an abnormal situation in the 3GPP system.